@Nullable
        static <T, A> SideEffect<T> fixedFrom(Value<A> value) {
            if (value.isMissing()) {
                return null;
            }

            return fixed(value.getWithoutSideEffect(), value.getSideEffect());
        }

        /**
         * Extracts the side effect from the {@code value} if any, and fixes it on that value.
         * <p>

            Value<? extends T> value = provider.calculateValue(consumer);
            if (value.isMissing()) {
                return value.asType();
            }

            collector.add(value.getWithoutSideEffect(), collection);
            return Value.present().withSideEffect(SideEffect.fixedFrom(value));
        }

        @Override
        public boolean isProvidedBy(Provider<?> provider) {

        withActualValue(it -> it.addAll(provider));
    }

    @Override
    public int size() {
        return calculateOwnPresentValue().getWithoutSideEffect().size();
    }

    /**
     * Adds the given supplier as the new root supplier for this collection.
     *
     * @param collector the collector to add

        Value<? extends Map<K, V>> result = value.calculateValue(consumer);
        if (!result.isMissing()) {
            return new FixedSupplier<>(result.getWithoutSideEffect(), uncheckedCast(result.getSideEffect()));
        } else if (result.getPathToOrigin().isEmpty()) {
            return noValueSupplier();
        } else {
            return new NoValueSupplier(result);
        }